Dynamic pressure bearing apparatus

Abstract

A dynamic pressure bearing apparatus provides a configuration in which the label on which desired data is visibly printed is arranged in a manner that the label does not overlap with a cover plate at least in the area where the label faces the rotary shaft in the shaft direction where the cover plate covers the opening of the bearing sleeve. Deformation of the cover plate that may occur during attachment of the label onto the cover plate is thus prevented. The position of the cover plate is leveled with the position of the label, which makes height reduction of the bearing apparatus possible. Subsequently, even when a relatively thick label is attached onto the frame, the dynamic pressure bearing apparatus can still be made thinner without adversely affecting performance or life thereof.

Description

TECHNICAL FILED OF THE INVENTIONThe present invention relates to a dynamic pressure bearing apparatus having a cover plate attached to the opening of a bearing sleeve that supports the rotary shaft via a lubrication fluid.BACKGROUND OF THE INVENTIONLately, among all types of rotary driving apparatus, the development of a dynamic pressure bearing apparatus that is essentially a rotor that rotates accurately at a high speed has advanced wherein a lubrication fluid generates a dynamic pressure to support a rotary shaft in the dynamic pressure bearing apparatus. For example, in the dynamic pressure bearing motor that is used for a hard disk drive illustrated in FIG. 5, rotary shaft 3 is rotatably inserted into bearing sleeve 2 having a hollow cylindrical shape and is attached to frame 1. A lubrication fluid is injected into a narrow gap between the dynamic pressure bearing sleeve 2 (hereinafter referred to as the “bearing sleeve”) and rotary shaft 3. A dynamic pressure bearing is thus c...

AI Technical Summary

Benefits of technology

According to the dynamic pressure bearing apparatus having the above configuration, a label does not overlap with a cover plate at least in the area where the cover plate faces the label. This eliminates the possibility of causing deformation of the cover plate when one attaches the label on the cover plate. Leaking of lubrication fluid due to deformation of the cover plate or the cover plate's contacting members at the rotary shaft end can thus be avoided.

Further, leveling the cover plate with the label in the shaft direction increases the longitudinal length of the bearing sleeve thus enhancing properties of the bearing. Alternately, leveling the cover plate and the label reduces the height of the dynamic pressure bearing apparatus, thereby providing a thin apparatus.

In another aspect of the dynamic pressure bearing apparatus, the label is made of a ring-like member that is formed in such a manner that the inner circumference is circular wherein an alignment guiding portion is provided along the hollow area, which is the inner end of the label's inner circumference, thereby enhancing accuracy of label placement along the aligning guide portion with ease of handling the label.

Consequently, the present invention is effective for a thin dynamic pressure bearing as it eliminates a rigid plate used for constituting a thrust bearing, and more specifically, configures a thrust bearing utilizing an edge of a bearing sleeve.

Problems solved by technology

This has provided an adverse effect on an attempt to reduce the longitudinal height of a dynamic pressure bearing apparatus.

This creates the possibility that the lubrication fluid may leak out from the open gap which is on the opposite end of bearing sleeve 2, subsequently deteriorating the bearing properties or lifetime of the dynamic pressure bearing.

Moreover, as is the case in the apparatus disclosed in Japanese patent application Laid-open (Kokai) No. 2001-289243, in an apparatus having a structure in which a lubrication fluid is filled in a space partitioned by the inner portion of the cover plate toward the bearing, the deformed portion of the cover plate may contact members toward the rotary shaft, causing abrasion or damage thereof.

The contact by the deformed cover plate contaminates contacted members, further contaminating the lubrication fluid in the dynamic pressure bearing.

Nonetheless, the longitudinal height of the dynamic pressure bearing apparatus increases by the amount that the rigid plate occupies, which is an undesirable effect on the demand for a thin bearing.

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